In the related art, non-contact communication systems represented by FeliCa (registered trademark of Sony Corporation) are widely being supplied.
The non-contact communication system includes a reader/writer (hereinafter, abbreviated as R/W) and a non-contact communication IC card (hereinafter, abbreviated as IC card). The non-contact communication system communicates information using electromagnetic waves between the R/W and the IC card in a non-contact type. Before various types of information are communicated, a mutual authentication process is executed. In place of the IC card, a mobile phone or the like is used in which an IC chip having the same function as the IC card has been built.
For example, information regarding a plurality of services such as an electronic money service, a commutation ticket service for an electric train or the like, and an employee ID card service is capable of being mounted on one IC card.
The access right or access method for user data within the IC card is controlled in a service unit. There is a key by which user data for each service is accessed. The right of access to user data corresponding to a T9 service is controlled by the above-described key. For each service, an access method is prescribed for use in a history data write method or an electronic money subtraction method.
To once execute a history data write process and an electronic money subtraction process, one key (degenerate key) is generated from keys of a plurality of services. It is possible to access the plurality of services by one mutual authentication process using the degenerate key. In this regard, it is possible to have access by executing a mutual authentication process using a key held for each service even in individual services.
In this regard, a mutual authentication process for each service is necessary to use a plurality of different services, that is, to access information regarding each service. When the mutual authentication process is executed using a different key for each service, the process becomes troublesome. Therefore, a technique has been implemented in which one key (degenerate key) is generated in advance on the basis of a plurality of keys respectively corresponding to services, and the degenerate key is commonly used in mutual authentication processes for the services (for example, see JP-A-10-327142).
When the above-described degenerate key is used, it is possible to reduce the time taken for the mutual authentication process and it is possible to quickly access information regarding a desired service.
However, for example, when a degenerate key is leaked in a situation where a plurality of IC cards uses a common degenerate key, it is necessary to change the common degenerate key held on the plurality of IC cards. Therefore, a method has been proposed for individualizing and using a degenerate key for each IC card by applying unique identification information (hereinafter, referred to as unique ID) of each IC card to a degenerate key without directly using the degenerate key (for example, see JP-A-2008-99335).